THE VOLATILE PART OF PLANTS. 61 



Mije-straio fiber. Linen fiber. 



Water 8.65 5.40 



Ash 3,05 l.U 



N 0.15 0.3S 



C 43.47 88.36 



H ' 6.04 5.89 



O 40.64 48.95 



100.00 100.00 



On deducting water and ash, and making proper correction for the 

 nitrogen, the above samples, together witli one of wheat-straw fiber, 

 analyzed by Henneberg, exhibit the following composition, compared 

 with pure cellulose. 



Itye-siraw fiber. Linen fiber. Wheat-straw fiber. Fiire cellulose. 



C 47.5 41.0 45.4 44.4 



H 6.8 6.4 6.3 6.3 



45.7 53.6 48.3 49.4 



100.0 100.0 100.0 100.0 



FrauzSchulze, of Rostock, proposed in 1857 another method for esti- 

 matinir cellulose, wliich bas recently, (1866,) been shown to be more cor- 

 rect tban the one already described. Kulm, Aronstein, and H. Schulze, 

 {Henneberg' s Jhurnal fiir LaiidwirUischaft, 1868, pp. 389 to 397,; have ap- 

 plied this metliod in the following manner : One part of the dry pulver- 

 ized substance, (3 to 4 grams,) which has been previously extracted with 

 water, alcohol, and ether, is placed in a glass-stoppered bottle, with 0.8 

 part of chlorate of potash and 13 parts of nitric acid of specific gravity 

 1.10, and digested at a temperature not exceeding 65° F. for 14 days. At 

 the expiration of this time, the contents of the bottle are mixed with 

 some water, brought upon a filter, and washed, firstly, witli cold and 

 after-wards, with hot water. When all the acid and soluble matters have 

 been washed out, the contents of the filter are emptied into a beaker, 

 and heated to 165° F. for about 45 minutes with weak ammonia, (1 part 

 commercial ammonia to 50 parts of w.ater) ; tlie substance is then brought 

 upon a weighed filter, and washed, first, with dilute ammonia, as long as 

 this passes off colored, then with cold and hot water, then with alcohol, 

 and, finally, with etliCr. Tlie substance remaining- contains a small 

 quantity of ash and nitrogen, for which corrections must be made. The 

 fiber is, however, purer than that procured by the other method, and a 

 somewhat larger quantitj', ()^ to IJ^ per cent,) is obtained. The results 

 appear to -vary but about omper cent from the truth. 



The average proportions of cellulose found In vnrioua -vegetable 

 mattera in the usual or air-dry state, are as follows : 



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